1. Field of the Present Invention
The present invention generally relates to the field of data processing systems and more particularly to a data processing system employing indicators to identify components of the system.
2. History of Related Art
Locating particular parts, referred to herein as field replaceable units (FRUs), in a large data processing system with multiple units in multiple racks within a large computer room can be difficult. Identify LEDs have been implemented on systems such as the IBM pSeries of systems to facilitate the identification of specific FRUs. When a FRU requires maintenance or replacement, an identify LED in proximity to the particular FRU is set to a blinking state to facilitate locating the FRU. While these identify LEDs are useful in locating a FRU, their usefulness is undermined if a blinking LED is not turned off after the FRU for which the LED is blinking has been serviced. This problem is of particular concern in a logically partitioned system because a system manager may not have access to identify LEDs that are part of another partition and is, therefore, at the mercy of the manager(s) of the other partitions.
Logical partitioning refers to the ability to make a single multiprocessor system, such as an AS/400e system from IBM Corporation, behave as if it were two or more independent systems. A system implementing logical partitions (LPARs) is referred to herein as an LPAR system. Logical partitions generally fall into two categories, namely, primary (or service) partitions and secondary partitions. Each logically partitioned system typically has a primary partition and one or more secondary partitions. Each logical partition represents a division of resources within the system. Each partition is referred to as “logical” because the division of resources is virtual, not physical. The primary resources in a typical system include its processors, main storage (system storage), I/O buses, and I/O adapters (IOA's). Each logical partition is configured to operate as an independent system, but each partition may share physical system attributes such as the system serial number, system model, and processor feature code. Other system attributes may vary among partitions. For example, each partition in a conventionally implemented LPAR may have dedicated hardware such as processors, main storage, and I/O devices.
Logically partitioned systems are gaining in popularity as a means of extending an enterprise's computing capabilities without expending resources on additional hardware. Dedicating a portion of a system's resources (disk storage units, processors, memory, and I/O devices) to a partition achieves logical isolation of software. Logical partitions also have some hardware fault tolerance if configured properly. Interactive and batch workloads that may not run well together on a single machine can be isolated and run more efficiently in separate partitions. Similarly, production and test environments can be implemented on a single physical system. Thus, a customer can consolidate several systems into one system with logical partitions thereby eliminating the need for, and expense of, additional equipment.
In large systems with multiple LPAR's, the number of FRUs may be very large. In this type of environment, identify indicators can be extremely valuable and even necessary. Consequently, the ability to keep the identify LEDs in their proper states is an important feature for systems employing such LEDs.